The study also bolsters recent research suggesting that bats are more closely related on the tree of evolution to horses, dogs, cows, moles and dolphins -- all members of the superorder Laurasiatheria -- than humans, monkeys, flying lemurs and mice, which belong to the Euarchontoglires superorder.

The resolution of the ancestral MHC class II structure requires an estimate of the time at which DY genes arose in order to judge whether Euarchontoglires, such as humans and mice, lost the DY subregion, or Laurasiatheria, such as carnivores and herbivores, gained the DY genes after the separation of Euarchontoglires and Laurasiatheria.